I recieved my SIMS a couple of days ago. I've several of these packages and so far I've not been able to assign the sims. I get "Unidentified package number" when I try to assign the SIMS to my account.
This is an older comment, but if you're like me, you are experiencing the same issue. I found that it was the site layout that was confusing me. I, too, got the same "Unidentified Package Number" error; however, I was finally able to find them and provision them.
I had to go to Quicklinks --> Provision available devices. Then in the "SIM inventory" dropdown box I selected SelfServe LTE/3G SIM, and my list of available SIM Cards populated.
Hopefully this will help someone else who is having trouble finding their SIMs in the interface after entering the 6 digit code.